Initially, its worth pointing out that the reason you are getting negative voted is that you have not structured your post in a way that enables people to respond. Ideally, subject line should contain the crux of your issue/question, with a detailed explanation of what you are seeing, what you are expecting, or a clear question about a gap in your knowledge.

In this instance I think you are trying to understand the parameters that Episerver Personalised Find uses to return individualised rankings, so that is how i'll respond.

Standard Find will use relevency that is tracked in the form of click-through rates. You can see this information in the statistics view of the standard Find interface.

Personalised Find will take this 'standard' crowd-based ranking and then pass it to the Personalised Find algorithms which will adjust the ranking using algorithms that are based on

1. commerce properties that are automatically ingested from your catalogue
2. tracking about the visitor's (individual) behaviour on the site (or anywhere else the tracking has been implemented)

So to have this working properly you need to have your commerce personalisation tracking implemented.

I hope this helped